Apparatus for determining the moisture content of grain, or the like



Dec. 27, 1966 G. SCHNATZ ETAL APPARATUS FOR DETERMINING THE MOISTURECONTENT OF GRAIN, OR THE LIKE Filed Feb. 28, 1963 l IIIIIIIIIIJIIIIIUIJ7. 7' INVENTORS Gusmv SCHNATZMCI L THAR RlcHTER Men 4710 Fri 25 UnitedStates Patent 3,293,907 APPARATUS FER DETERMINING THE MQESTURE QtlNTENT@F GRAIN, UR THE LEKE Gustav Schnatz, 11 frchone Aussicht, Maschen,Hat-burg,

Germany, and Lothar Richter, l9 Winsener Landstrasse, Fieestedt,Harhnrg, Germany Fiied Feb. 28, 1363, Ser. No. 261,738 Ciaims priority,appiication Germany, Feb. 28, 1962, Sch 31,058 6 Claims. (Ci. 73-73)This invention relates to rotary testing apparatus for cyclicallydetermining the moisture content of grain, or the like, based on asample which is ground and introduced into a measuring container andcompressed therein, the measuring container comprising means formeasuring the electrical resistance and the temperature of the sample.

When drying and storing grain, or the like, it is necessary to determineits moisture content either at regular intervals, or continuously.

Generally the above mentioned measurements are required when grain,or'sirnilar material, is delivered for storage, since the moisturecontent is a controlling factor with regard to storage time and price.If these measurements show a too high moisture content, the grain is'fed to a dryer whereupon, after drying, the moisture content must bedetermined again. In conventional practice, the samples are manuallyremoved from a stream of grain at timed intervals and are then measuredin a laboratory. However, from the time of taking the sample until themeasurement results are known, a certain time is lost depending onvarious factors and, during this time, grain having an objectionablemoisture content is delivered to the storage facility or to the dryer.Moreover, samples are usually removed from a large quantity or batch ofgrain and practice has shown that such samples do not always reflect theactual moisture content of the entire batch although the batch is wellmixed. Since the samples are taken manually generally every half hourthere is no assurance that the representative moisture content for allof the grain is actualy measured.

Therefore it is an object of the invention to provide a rotarycyclically operative apparatus for repeatedly determining the moisturecontent of grain, and which will determine the moisture content of acontinuously conveyed fiow of grain at very short time intervals, ornearly continuously.

Briefly, the measurement container and grinding means are arranged forrotation as a unit about a substantially horizontal axis and with theirinner chambers communicating with each other in such a way that thesample will flow from the grinding means into the measuring containerand vice versa by gravitational action.

Preferably this is accomplished in such a manner, that the measuringcontainer includes two openings, each being separately closable by asuitably controlled slide, one of the openings communicating with theinner chamber of the grinding means while the other opening forms aninlet for the sample to be measured. By means of this arrangement, asample amount may be removed from a flow of grain without manualoperation and may be introduced into the chamber of the grinding meansfrom where it is automatically passed into the measuring container bygravitational flow after the grinding is finished and the moisturecontent is measured using the measuring electrodes provided within thecontainer. Because the measuring container is eccentrically mounted forrotation with the grinding means, all of the movements of the samplerequired for the measuring are produced by gravity and mayadvantageously be controlled in accordance with the angular position ofthe measuring con- 3,293,97 Patented Dec. 27, 1966 tainer and thegrinding means, so that the measuring apparatus will operateautomatically. Due to this it is possible to install the apparatusaccording to the inven tion directly at the conveyor, or mount itthereon respectively, whereby transportation of the sample to thelaboratory is omitted. An etfectively continuous measurement, or ameasurement repeated at very short time intervals of a few minutes isthus made possible so that between succesive measurements only a smallamount of material will pass the sampling bone. When dryers are used,the measured values of moisture content may be translated intoelectrical control impulses for regulating the action of the dryer.

In the drawings:

FIG. 1 is a schematic sectional view of measuring apparatus embodyingthe invention; and

FIG. 2 is an enlarged fragmentary sectional view showing the measuringcontainer and the grinding means of the apparatus according to theinvention.

The measuring apparatus comprises essentially two important members, thegrinding means 1 and a measurement container 2. The interior chambers ofthe grinding means and of the measuring container are connected togetherso that a sample may pass from the measuring container to the grindingmeans and vice versa. The measuring container 2 is provided with twolaterally spaced resistance measuring electrodes 3 and temperaturemeasuring means 4 which may be a thermometer, a thermocouple element, orthe like. The measuring electrodes 3 as well as the temperaturemeasuring means 4 are connected to suitable indicating or otherutilization means (not shown).

The measurement container 2 and the inner chamber of the grinding means1 may be shut off from each other by a radially inner cam-actuated slide5. An inlet opening 6 of the measurement container 2 may be shut offfrom the interior of the container by a radially outer cam-actuatedslide 7. Once during each revolution of the apparatus, and when themeasurement container is upwardly directed, the inlet opening 6 isbrought into axial alignment or register with an inlet tunnel orreceiver 8 for the sample, whereby a sample of predetermined volume maybe metered and passed via the container 2 into the grinding means 1 withthe slides 5 and 7 both open.

After the sample arrives within the grinding means 1, it will start tooperate. As shown, the grinding means may operate continuouslyindependently of the presence of material to be ground. During grinding,the upper slide 7 is closed so that the sample is ground underconditions which exclude air and prevent the escape of moisture. Theclosure of the slide 7 is suitably achieved by the fact that thegrinding means together with the measuring container are pivoted on ahollow counterclockwise rotating shaft 9 which extends axially at thecenter of a stationary cylindrical drum it) so that the slide 7 engagesa fixed arcuately extending slide-actuating cam 11 at the angularposition A.

Details of the construction of the cam 11 and cooperating slide 7 havebeen omitted for simplicity of illustration. The cooperation is such,however, that the slide 7 is positively actuated by the cam 11 both foropening and closing, the slide 7 being continuously closed throughoutthe arcuate extent of the cam 11 from angular position A proceedingcounterclockwise to position E and open from angular position Eproceeding counterclockwise to position A. The cam 11 is thus adoubleacting cam. Any conventional arrangement may be used, such as acam-follower roller guided between the lateral walls of a camming slot,a biasing spring ar' rangement for open-ing the slide, a slotted camfollower which is positively actuated by a fixed camming lip engaged inthe slot, or any other convenient means for causing the opening andclosing sequence for the slide 7 as described above. Because of theirmanner of operation, the slide controlling cams are hereinatfer referredto, for convenience, as double-acting cams.

Thereafter, the grinding means with the measuring container continues torotate counterclockwise to the position B where the drive of thegrinding means is preferably switched oft by cam-actuated means (notshown). After stoppage of the grinding means 1 and furthercounter-clockwise rotation of the shaft 9, the position of themeasurement container 2 changes relative to the inner chamber of thegrinding means 1, whereby the ground material contained in the grindingmeans fiows by gravity into the measuring container 2. In the position Cthe entire sample has been transferred to the measurement container 2and the slide 5 is closed by a fixed double-acting arcuate control cam12. Thus, the sample is confined in the temperature and moisturemeasurement container 2 and the measuring procedure may take place.

The measuring procedure also includes the compression of the groundsample of the goods which is achieved by the invention in such a waythat a telescopically arranged spring loaded coaxial extension 13 of themeasuring container 2 is yieldingly urged axially outwardly of themeasuring container. This tubular extension 13 carries the outer slide 7so that the volume of the measurement chamber of the measuring container2 may be decreased and the sample compressed. The compressive movementof the telescoping extension 13 is obtained in a simple manner byengagement of a shoulder of extension 13 with a fixed control cam 14.After the compression is completed at position D, the electricalmeasuring electrodes and the temperature measuring means are utilizedand the measurements are made while the rotating movement of the shaft 9carrying the grinding means and the measuring container is momentarilyinterrupted. This interruption is suitably timed and is terminated afterthe measurements are completed. Thereupon shaft 9 resumes its rotationand the compression of the sample is discontinued by disengagement ofthe extension 13 from the control cam 14. This abrupt release causesloosening of the sample compressed in the measuring container whereupon,at the position E, the slides 5 and 7 are opened by the double-actingcams 12 and 11, respectively, and compressed air is blown into the innerchamber of the grinding means 1 via the duct 15. Thereby the spentsample is blown out and drops downwardly through the inlet opening 6 andthe outlet opening 16 in drum into a storage bin (not shown).Simultaneously, the grinding means may start operating again tofacilitate by its movement the pneumatic discharge of the measuredsample. At the position F the supply of compressed air is shut off andthe measuring container and the grinding means return after furtherrotation into the starting position shown in FIG. 1 in which the axis ofthe grinding means and of the cylindrical measuring container extendsubstantially vertically upwardly.

Preferably the measuring apparatus is mounted in such a way that, exceptfor the remote measuring means (not shown), it is enclosed within aclosed cylindrical drum 10 adapted to be directly mounted at thelocation where the sample is taken. The drive for the rotating movementmay comprise an electric motor (not shown) connected to the shaft'9.

What is claimed is:

1. Grain testing apparatus of the class described, comprising: astationary drum; grinding means disposed within said drum for rotationabout a horizontal axis coaxial with said drum; sample receiving meanscarried by said drum and extending outwardly thereof for receiving asample of the grain to be tested; means defining a radially extendingaxially compressible elongated measurement chamber communicating withsaid grinding means and connected for rotation therewith, saidmeasurement chamber being positioned eccentrically with respect to therotational axis of said grinding means for gravitational filling anddischarge of the sample therefrom, an outer end portion of saidmeasurement chamber being brought into register with said samplereceiving means when said chamber is in an upwardly directed position,said drum having an outlet aperture formed therein wherewith said outerend portion 'of said measurement chamber in register when said chamberis in a downwardly directed position; temperature measurement meanswithin said chamber; electrical resistivity measurement electrode meanswithin said chamber; first cam-actuated slide means for selectivelyshutting off communication between said measurement chamber and saidgrinding means; second cam-actuated slide means for selectively shuttingoff communication between said outer end portion of said chamber and theinterior thereof; resilient means biasing said chamber to elongate thesame; fixedly positioned first cam means within said drum, said firstcam means operating to open both of said slide means when said outer endportion of said measurement chamber is in register with said samplereceiving means for delivery of said sample to said grinding meansthrough said measurement chamber and to close said second slide meanswhen said outer end portion moves out of register with said receivingmeans, said cam means closing both of said slide means when saidmeasurement chamber has arrived at a downwardly directed position andsaid grinding means has gravitationally discharged the sample in groundcondition into said chamber; second cam means acting on the outer endportion of said means defining said measurement chamber when both ofsaid slide means are closed to compress said chamber whereby apredetermined pressure is applied to said sample, rotational movement ofsaid chamber being interrupted wit-h said pressure applied to permitmeasurement of the temperature and electrical conductivity of saidsample, said pressure being released by said second cam means after saidrotational movement has been resumed; said first cam means opening bothof said slide means after release of pressure by said second cam meansand with said outer end portion of said chamber in register with saidoutlet aperture.

2. Apparatus according to claim 1, further comprising pneumatic meansoperative when said outer end portion of said chamber is in registerwith said outlet aperture for blowing said sample out of said chamber.

3. Apparatus according to claim 1, wherein said measurement chamberdefining means comprises two telescopically arranged tubular members.

4. Grain testing apparatus of the class described, comprising: grindingmeans mounted for rotation in a predetermined direction about ahorizontal axis; sample receiving means positioned above said axis forreceiving a sample of the grain to be tested; means defining a radiallyextending compressible measurement chamber communicating with saidgrinding means and connected for rotation therewith, said measurementchamber being positioned eccentrically with respect to the rotationalaxis of said grinding means for gravitational filling and discharge ofthe sample therefrom, an outer end portion of said measurement chamberbeing brought into register with said sample receiving means when saidchamber is in an upwardly directed position; outlet means wherewith saidouter end portion of said measurement chamber in register when saidchamber is in a downwardly directed position; temperature measurementmeans within said chamber; electrical resistivity measurement electrodemeans within said chamber; first slide means for selectively shuttingoif communication between said measurement chamber and said grindingmeans; second slide means for selectively shutting off communicationbetween said outer end portion of said chamber and the interior thereof;resilient means biasing said chamber against compression thereof; firstactuating means operating to open both of said slide means when saidouter end portion of said measurement chamber is in register with saidsample receiving means for delivery of said sample to said grindingmeans through said measurement chamber and to close said second slidemeans when said outer end portion moves out of register with saidreceiving means, said actuating means closing both of said slide meanswhen said measurement chamber has arrived at a downwardly directedposition and said grinding means has gravitationally discharged thesample in ground condition into said chamber; second actuating meansacting on said measurement chamber when both of said slide menas areclosed to compress said chamber whereby a predetermined pressure isapplied to said sample, measurements of the temperature and electricalconductivity of said sample being made with said sample compressed, saidpressure being released by said second actuating means after furtherrotational movement of said measurement chamber; said 20 ReferencesCited by the Examiner UNITED STATES PATENTS 1,890,545 12/ 1932 Limbrick73-73 2,082,364 6/ 1937 Store. 2,343,340 3/ 1944 Stevens 737 3 2,520,3948/1950 Franzen-Lutz et al. 324-65 FOREIGN PATENTS 885,306 12/ 1961 GreatBritain.

RICHARD C. QUEISSER, Primary Examiner.

DAVID SCHONBERG, JAMES J. GILL, Examiners.

LAWRENCE R. FRANKLIN, Assistant Examiner.

1. GRAIN TESTING APPARATUS OF THE CLASS DESCRIBED, COMPRISING: ASTATIONARY DRUM; GRINDING MEANS DISPOSED WITHIN SAID DRUM FOR ROTATIONABOUT A HORIZONTAL AXIS COAXIAL WITH SAID DRUM; SAMPLE RECEIVING MEANSCARRIED BY SAID DRUM AND EXTENDING OUTWARDLY THEREOF FOR RECEIVING ASAMPLE OF THE GRAIN TO BE TESTED; MEANS DEFINING A RADIALLY EXTENDINGAXIALLY COMPRESSIBLE ELONGATED MEASUREMENT CHAMBER COMMUNICATING WITHSAID GRINDING MEANS AND CONNECTED FOR ROTATION THEREWITH, SAIDMEASUREMENT CHAMBER BEING POSITIONED ECCENTRICALLY WITH RESPECT TO THEROTATIONAL AXIS OF SAID GRINDING MEANS FOR GRAVITATIONAL FILLING ANDDISCHARGE OF THE SAMPLE THEREFROM, AN OUTER END PORTION OF SAIDMEASUREMENT CHAMBER BEING BROUGHT INTO REGISTER WITH SAID SAMPLERECEIVING MEANS WHEN SAID CHAMBER IS IN AN UPWARDLY DIRECTED POSITION,SAID DRUM HAVING AN OUTLET APERTURE FORMED THEREIN WHEREWITH SAID OUTEREND PORTION OF SAID MEASUREMENT CHAMBER IN REGISTER WHEN SAID CHAMBER ISIN A DOWNWARDLY DIRECTED POSITION; TEMPERATURE MEASUREMENT MEANS WITHINSAID CHAMBER; ELECTRICAL RESISTIVITY MEASUREMENT ELECTRODE MEANS WITHINSAID CHAMBER; FIRST CAM-ACTUATED SLIDE MEANS FOR SELECTIVELY SHUTTINGOFF COMMUNICATION BETWEEN SAID MEASUREMENT CHAMBER AND SAID GRINDINGMEANS; SECOND CAM-ACTUATED SLIDE MEANS FOR SELECTIVELY SHUTTING OFFCOMMUNICATION BETWEEN SAID OUTER END PORTION OF SAID CHAMBER AND THEINTERIOR THEREOF; RESILIENT MEANS BIASING SAID CHAMBER TO ELONGATE THESAME FIXEDLY POSITIONED FIRST CAM MEANS WITHIN SAID DRUM, SAID FIRST CAMMEANS OPERATING TO OPEN BOTH OF SAID SLIDE MEANS WHEN SAID OUTER ENDPORTION OF SAID MEASUREMENT CHAMBER IS IN REGISTER WITH SAID SAMPLERECEIVING MEANS FOR DELIVERY OF SAID SAMPLE TO SAID GRINDING MEANSTHROUGH SAID MEASUREMENT CHAMBER AND TO CLOSE SAID SECOND SLIDE MEANSWHEN SAID OUTER END PORTION MOVES OUT OF REGISTER WITH SAID RECEIVINGMEANS, SAID CAM MEANS CLOSING BOTH OF SAID SLIDE MEANS WHEN SAIDMEASUREMENT CHAMBER HAS ARRIVED AT A DOWNWARDLY DIRECTED POSITION ANDSAID GRINDING MEANS HAS GRAVITATIONALLY DISCHARGED THE SAMPLE IN GROUNDCONDITION INTO SAID CHAMBER; SECOND CAM MEANS ACTING ON THE OUTER ENDPORTION OF SAID MEANS DEFINING SAID MEASUREMENT CHAMBER WHEN BOTH OFSAID SLIDE MEANS ARE CLOSED TO COMPRESS SAID CHAMBER WHEREBY APREDETERMINED PRESSURE IS APPLIED TO SAID SAMPLE, ROTATIONAL MOVEMENT OFSAID CHAMBER BEING INTERRUPTED WITH SAID PRESSURE APPLIED TO PERMITMEASUREMENT OF THE TEMPERATURE AND ELECTRICAL CONDUCTIVITY OF SAIDSAMPLE, SAID PRESSURE BEING RELEASED BY SAID SECOND CAM MEANS AFTERROTATIONAL MOVEMENT HAS BEEN RESUMED; SAID FIRST CAM MEANS OPENING BOTHOF SAID SLIDE MEANS AFTER RELEASE OF PRESSURE BY SAID SECOND CAM MEANSAND WITH SAID OUTER END PORTION OF SAID CHAMBER IN REGISTER WITH SAIDOUTLET APERTURE.